The thought of eating before an early morning workout can leave some people feeling a little nauseous, but it’s actually highly recommended to eat something, as your body will perform better. During exercise, your body uses stored forms of carbohydrates in your liver and muscles, which are called glycogen.
Your liver breaks down the glycogen as you sweat to maintain your blood glucose levels. Your body stores enough glycogen to support you through a short workout, once this is used up it will use fatty acids for fuel.
Some believe that if you work out on an empty stomach your body will break down the fatty acids sooner, this does happen if you are doing a low to moderate-intensity workout. But in the long term, the effects diminish as the workout intensity increases.
If you skip your pre-workout meal or snack, this could lead to nausea, fatigue, and lightheadedness while you’re working out. A low-intensity workout can be done fasted, like a short walk or a 20-minute yoga class. If you’re lifting weights and working out for 45 minutes to an hour, eating something you will allow the body to have more energy, power, and stamina.
If you train regularly, not eating before a workout can have an effect on how you recover. When you begin your workout in a fasted state, your blood sugar is most likely already low, so you will use up the available glycogen, leaving not enough for your recovery period. If your muscles don’t have enough fuel then this will decrease recovery in the long run.
You can do a fasted workout once in a while, but don’t let it become a habit. If you’re strength training you most likely want to build your muscles and get stronger, but if you aren’t eating before, your muscles will start to feel tired sooner into the workout than they would have if you had eaten.